INSTALLING WWW::Mechanize::Chrome
Install the chrome
executable
WWW::Mechanize::Chrome
requires that you have the Chrome browser installed on your system. If Chrome is not installed, please consult Google's instructions for help installing the Chrome browser.
WWW::Mechanize::Chrome
will do its best to locate Chrome's executable file on your system. With any luck, it will find the executable you want to use. If WWW::Mechanize::Chrome
does not find Chrome on your system or you want to use a different executable, you can use the launch_exe
constructor argument to tell WWW::Mechanize::Chrome
where to find it. You can alse set the CHROME_BIN
environment variable to the absolute path of the executable.
Test the chrome
executable
You should verify that Chrome's executable is working properly. On Ubuntu, the executable is typically named chrome-browser
and so you can test Chrome's installation with:
chrome-browser --version
and you should see something like Google Chrome 67.0.3396.99
returned.
Note that the command you run will vary based on your operating sytem and possibly the version of Chrome installed.
On a Debian system, for example, the command will most likely be something like:
google-chrome-stable --version
or google-chrome-beta --version
or google-chrome-unstable --version
On Windows, the executable is named chrome.exe
and doesn't output information to the console but you can check that Chrome starts by running:
chrome
in the terminal.
On MacOS, the executable can usually be be found inside the Google Chrome.app
package in the /Applications
directory and its installation can be tested with something like the following:
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version
or, if Chrome is installed for a single user:
/Users/<user_name>/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --version
If you are having trouble finding, installing, or running Chrome on your system, please consult the appropriate documentation or a knowledgeable expert.
Chrome versions
Note that the Chrome version numbers do not denote availability of features. Features can still be added to Chrome v62 when Chrome v64 is already out.
If you are serious about automating a website, use a separate copy of Chrome and disable its automatic updates.
Module prerequisites on OSX
Imager::File::PNG
This module relies on Imager for processing screenshots. If you don't need this functionality, you can ignore the Imager and Imager::File::PNG installation and use this module with the system Perl provided by Apple.
The installation of Imager::File::PNG works on OSX using the Homebrew tool and the Perl installable through Homebrew:
brew install perl-5.28
brew install libpng
cpan Imager::File::PNG
I haven't been able to make it work using the system Perl.
RUNNING THE TEST SUITE
The normal test invocation is 'make test'.
If your executable has a different name than chrome-browser
or chrome.exe
or is not in your path, then set the environment variable CHROME_BIN
to the absolute path.
If you have Chrome already running, it must have been started with the <--remote-debugging-port=9222
> option to enable access to the developer API. You may want to set up a dedicated and version pinned version of Chrome for your automation.
Running Chrome on a different X display
All supported versions of Chrome support the headless mode now. If you want to observe what the browser is doing on a different X display, you can achieve that by (1) not running any chrome binary and (2) start a separate display with Xvfb and (3) set the DISPLAY variable accordingly. E.g.:
Xvfb :121 &
DISPLAY=:121 CHROME_BIN=/usr/bin/google-chrome-stable make test
INSTALLING CUSTOM VERSIONS OF CHROME
When doing serious testing, automation or scraping, you want to use a separate instance of the browser. You should install it into its own directory and disable automatic updates.
Windows
Woolyss.com keeps an archive of old Chrome builds. Download the "Archive" version you want from here and unpack the archive it into its own directory:
https://chromium.woolyss.com/#windows-64-bit
You can then use the custom Chrome executable by setting (for example)
set CHROME_BIN=C:\Scraping\chrome-versions\chrome-win32-78.0.3904.0\chrome.exe
Debian (Linux)
This site keeps an archive of old Chrome builds for Linux. Download the "Linux_portable" version you want from here and unpack the archive it into its own directory:
https://ungoogled-software.github.io/ungoogled-chromium-binaries/releases/linux_portable/64bit/
These packages are supposed to work on any supported Linux distribution.